The lower surface of a human body lying on a bed receives the force of gravity of the upper part of the human body. Circulating system organs such as blood vessels and lymphatic vessels are pressed and their functions arc degraded. A healthy person can turn on the bed to change the bodily area pressed by the force of gravity and maintain normal functions of the circulating system.
However, elderly persons forced to always lie on bed or patients applied with an anesthetic cannot turn on the bed with their own forces, and the same lying posture on beds is forced to be maintained. As a person lies on a bed for a long time with the same posture, the lower part of the body on the bed is pressed by the gravitational force and the circulation system function is degraded so that the body has bedsore. In order to prevent bedsore, it is necessary to prevent a pressure (bodily pressure) from being applied to the body at the same area.
An air mat has been developed which can prevent bedsore. This air mat is constituted by a plurality group of air cells and compressed air is selectively introduced into each air cell group. If the compressed air is intermittently supplied, the surface area of a human body on the air mat is released from the bodily pressure during the period while the compressed air is not supplied so that the functions of circulating system organs can be recovered.
For example, an air mat on which a person Lies is constituted by a number of air cells, and the air cells are divided into two groups to which compressed air is alternately supplied. In this manner, even if a person lies on the air mat at the same posture, the area receiving the bodily pressure changes. Since the area receiving the bodily pressure changes, bedsore can be prevented.
With such an air mat, nursing work for a person, who cannot move the body with own force such as an always lying elderly person, can be reduced considerably.
In a surgical operation, the patient under operation is applied with an anesthetic or the like and cannot change the posture with own force. For a doctor performing an operation, it is necessary to maintain the same posture of the patient. In order to prevent bedsore of the patient under operation, an air mat capable of changing the area supporting the patient weight is very effective.
During an operation, a doctor moves his or her body and the temperature of the doctor rises. If the temperature of the operation room is high, the doctor sweats and there is a danger that the sweat drops on the affected part of the patient. From this reason, the temperature of an operation room is generally cooled to about 22.degree. to 25.degree. C.
A patient under operation maintains the same posture during the operation. In many cases, the patient is applied with an anesthetic so that the metabolism lowers. If a patient is left in the cooled room for a long time, the temperature of the patient lowers. The patient who lowers the temperature during an operation reduces the physical strength. As the physical strength of the patient under operation reduces, the recovery of the physical strength after the operation is hindered.
It is therefore desired to maintain the temperature of a patient under operation at a predetermined level.
Japanese Patent Laid-open Publication No. 60-129918 discloses an air mat having code heaters disposed at connection sections between adjacent air cells. Each air cell is made of a rubber or synthetic resin sheet and disposed adjacent, to other air cells to form the bed surface. There is a gap between adjacent cells and the code heater is disposed in this gap.
However, if the air mat having this structure is used as the air mat for an operation bed, the following problems occur. The patient under operation maintains a constant body posture during the operation. For convenience of a doctor performing an operation, an air mat for an operation bed cannot be made thick. If local heating is performed by a code heater, it is not easy to uniformly heat the patient body. A temperature distribution is likely to be generated on the body surface of the patient. It is therefore desired to perform uniform heating.
A bodily temperature recovery apparatus has also been developed which covers the body of a patient after the operation and blows heated air therein in order to recover the patient temperature lowered during the operation.